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A. T. CARTER. v PROTECTIVE DEV| CE FOR ELECIRIC INTERLOCKING SYSTEMS. 1,313,879.

APPLICAT ION FILED MAY]. 91]- Patented A11 26, 1919. 3 SHEETS-SHEET l- F'IG. 1.

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THB col-UMBIA FLANOGRAPH co., WASHINGTON, D. c.

v A. T. CARTER. PROTECTIVE DEVICE FOR ELECTRIC INTERLOCKING SYSTEMS.

I APPLICATION FILED MAYI. I917. I 1,313,879. v PatentedAug. 26,1919.

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A. T. CARTER. y PROTECTIVE DEVICE FOR ELECTRIC INTEBLOCKING SYSTEMS.

APPLICATION EILED MAY 1 i9 7 Patented Aug. 26, 1919.

S SHEET s.

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i To all whom izf'may concern iinrrn' AINSLIE rqcnn'rnaor nocnnsrnn NEW YORK, AssIGNon. TO GENERAL mnnwnv ,SIGNAL COMPANY, OF .G'ATES, NEW. YORK, .A GOBPORATION'I O F NEW"YORK.

PROTECTIVE DEVICE non nnnc'rmc nrnnnocmue sysrnirs.

. Be it known thatI, AINsLrn T. CARTER',-a cltizen of the United States, and resident of the c1ty of Rochester, in the county of Monroe and State of New York, have invented a new and useful Protective Device for Elec- H tric Interlocking Systems, of which the following is a specification.

This invention relates to electric interlocking systems for railroads, and more particularly to a protective device which is designed for use in connection with such systerns operated by alternating current, and

which is capable of protecting the system against improper operation of the parts or functions due to crosses between operating wires and similar derangements of the wiring)and connections. ne of the principal objects of this invention is to devise a simple and reliable protective device which will eifectively protect the function or functions under its control from improper operation due to crosses or the like.

' A further object of the invention is to de-' vise aprotective device which can be restored to its normal cond tion after it has 1 been automatically operated, but which cannot be manipulated accidentally or intentionally in such a way as to interfere with or destroy the'protection which'it gives.

A still further object of the invention is to devise a protective devicev which, after being automatically operated by an improper flowof current. due to a cross or the like, cannot be permanently restored to nor held improperly in its normal condition to reestablish a path for said improper flow bf current, until the cross or other condition causing such improper flow of current has a ceased to exist.

, Other objects and advantages of the invention will appear more fully hereinafter during the description of the particular embodiment of the invention selected to explain its principles of operation and features of construction; and the novel features of the invention will be particularly'pointed out in the appended claims.

In describing the invention in detail, reference is made to the accompanying drawings, in which is illustrated a preferred 7 physical embodiment of the invention,

earns PAT NT OFFICE. 'j

Specification ofLetters Patent. -P a,tenfed Aug- 26, 19 19; Application filedlviay 1,1917; 's'e ri ifno. 165,691. 1

which like reference characters designate corresponding partsin tlieseveral views, aI-1d.

in which; a "Figure l is'a top planview of the fprotecf t'ive device embodying the'inv ention, part of theupper part or casing of-the device being broken away to show the parts underneath;

Fig. 2 is ,a vertical longitudinal section taken substantially on-theline 2- 2 in Fig 1 and looking in the direction indicated by the arrows, part of the casingfbeing rem Fig. 3 is a vertical transverse section through the protective device taken substan tially on the line 3+3 inFig. 2 and looking toward the right in the. direction indicated by the arrows; f- I I Fig. 4 is another verticaltransvlerse section taken substantially on the line H in 2 and looking-toward the right in the direction indicated by the arrows;

Fig. 5 is an enlarged view of some of the significant operating parts of the device detached and shown in the operated position;

Fig.6 is a detail plan view of the handle 1 constituting part of the protective device and shows the manner in which this handle is mounted, part of the handle being broken away;

Fig. of a lever constituting a part of the protective device;

Fig. 8 shows a side view and a top plan view of a member constituting apart of the protective device and herein referred to asa vane support;

Fig. 9 shows a side and an end view of a shaft constitutingpart ;0f the protective'device v l FigflO is a diagrammatic illustration, in

the nature of a wiring diagram, showing the application of the protective device'embodying the invention to a system of electric in terlocking;

7 shows a side view and an edge view 'ment alternating current relay, specifically v bers connected by mtegral upper and lower cross members 8 and 9, respectively. .Intepassing between thepole piecesofithejcore 4 I a relayofthevane typeptogetherfwith as-V ,deviceas illustrated isl forin v v like framecomprising two metallic end cast-i' ,sooiated' contactj devices adapted to be opened upon energi'zation of the relay, "and V manually .controlled restoring devices for; permittingthe closing of the'contacts'of the relay'under safeconditions. The protective ed with a-boxingR and Fyand top and bottom blocks of ons-er ale enacasnng which the entire protective device 'is secured to a suitable supporting panel, and for convenien'c'this end of the [protective device will behereinafter termedflthe rear end. a "@The rear end casting R'has formed-in tegral therewithtwo side arms 3 which ex tt end' substantially parallel with each other I toward theffront'end of the protective device. 'Onthearinsl3'issupported a stacking of laminations constituting a core ,4: of a general rectangularv shape, said core being One fastened tofthe arms 3iby screws. 5.

side; of the core rcarriesa coil 6,"and the limbs of the opposite sidefcarry shade rings 7 in' the same way 'and'forkthe same purpose commonly employedin the construction ofvane'typerelaysf i The front .end casting'F-hasthe general form of'a hollow square, as shown in Figs.

3 and 4E, and consists ofvertical sidemem gral with the side members of. the. front? end 1 casting F are rearWa-rdly extending'lugs 10 (see Figs." 3 and 4) and. screwedinto holes in said lugs; :10 are bearing screws11'which form supportsfor the ends of a transverse pinor shaft 12. Mounted on the transverse shaft '12 is a memberdesignated as a whole 4360 graltherewith alaterally extending pin 18 Y by theletter S and herein referred'to as the V vane support, this member being shown de-' 7 tached in Fig. 8. As illustrated,1this vane support S comprises a flange 13 to which-is riveted or otherwise suitably fastened a sector-shaped'vane 14;, the, free end of thevane in the usual way; The vane support S :is also formed with upwardly and downwardly extending projections ther comprises bifurcations'16, including infor the purpose hereinafter described.

Also mountedon the 12 between the v .15, formed with flat f contacting surfaces forlthe purpose herein 7 '3jand 5) the ends ofwhich after explained; and the vanesupport S fursaid member'31and constitute pivot pins for r the ends of two links 34 (seeFig. suit;

arms 15;of thevane support S is a lever'L, showg rdetached in Fig. 7. v This leverL is formed with a curved shoulder 19 nearits' middle, an inclined face' 20 near its lower endand a V-shaped notch 21 in its upper with aV-shaped head engaging the notch 21 in I said lever, and which through, a ftransver'se' hole in plunger being interposed between its head and:said shafuas clearly shown in Figs. 2 and 5. i The shaft 2-fexten'ds transversely of passes loosely 7 V a shaft 24, a; compression coil spr ng 25 surroundmg sand front end casting Disposed above thea lever L is a plu'nger '23 which is provided :7 5

the-protective device and is formed fatits ends with 'knife. edge bearings 26.,which L bearagainst the edges of holes formed in lugs 27 projecting rearwardly from theup per cross member F (see1Figs.3 and Located in front' of the' vane support 8of the front, end casting.

andthe lever L, and also'supported so as to turn about ahorizontal axis, is the restoring handledesignated as-a wholeby the letter hubs or bosses 28 (see'Fig. 6) which are journaled on pivot pins 29; adjustably mounted inthe side members of the front end casting. F. The restoring'handle Hjis providedwith arearwardlyextending lip I i or lug 30, the upper face of which fis curved and is adapted to engagewith'the curved 1 shoulder 19 of thelever L. "The/shoulder 19 and thelip130 are preferably'shaped. in ac cordance Withthe same principles governing the shapeof gear teeth in order that aslittle friction as possible will occur when the ire-j storing handle H andthe lever rock' on their respective axes. The restoring'handle standing projecting portionlSl, the upper H. .This restoring handle H is formed with a v V -H:is also providedi'with'aniintegraliup L end of, \vhichisadapted to strike the lower edge of the upper crossi nemher S of the .end casting F, as shown in Figs. 2 and Surrounding one of the pivot pins 29 is a torsion'spring 32, one endof which is anchored to .thehandle H, and-the other end ofwhichis anchored to the front'end cast: ingI" F, vas clearly showninFig. '6.

he upward "projectingfportion 31 of' the handle H is provided with a transverse bore inwhlch is mounted a pin 33', (see Figs. 2, extend beyond able pins or retaining devices being inserted through the 'pin 33 t'o holdsaidlinks-in place; pThe air of links. 34 extend substan tially parallel rearwardly from the handle 7 H and at their rear ends slots formed in the ends ofanother pair of links 35; and a are disposedin 1 1 I of the pair of links85 are also slotted and-- are ivotally connected by pins 38 (see Figs. 1 and 2) to small brackets 39. fixed to contactfingers 40. The'contact fingers 40 are arranged substantially'vertical and are fas-' tened at their lower ends to the bottom insulating block B by binding post 41;" and the upper ends of the contact fingers 40 are adapted to make electrical contact with contact pieces 42 fastened 'to angle-shaped con ducting bars which are in turn secured to the top insulating block T by bolts-43 or other suitable fastening means, said angle shaped pieces being preferably formed with slots through which the bolts 43; pass so as to facilitate adjustment ofthe contact pressure by adjusting said angle-shaped pieces rather than by bending the contact fingers 40. EX

tending rearwardly from the front end casting F are two parallel side brackets 44" in which are adjustably mounted screw stops 45, Said stops 45 being located immediately below the links (see'FigL 4) near 'the front endof said links.

It is sometimes desirable for various reasons to be able to manually trip the protective device and open its contacts; and for this purpose a plunger 46 (see Fig. 5) 1s carried by one of the side members of the front end casting F in a position such that its enlarged head will strike against the pin 18 integral with the vane support S. Fastened to the forwardly extending end of the plunger 46 is a button 47, and surrounding the plunger 46 is a compression spring 48 which bears at one end against the button 47 and at its other end against the botto'in V of a recessin the'outer face of said side member.

"In order to prevent unauthor1zed interference withtheprotective device, theopcrating parts thereof are preferably inclosed.

The construction of the main skeleton er frame work of theprotective device-incloses the operating parts on'the top and bottom, and the rear end, but leaves the two sides and the front end open. These two s'idesand frcnt'endare preferably covered by a cover 51 having a general U-shape which is slid in rabbets formedflin the top and bottom insulating blocks T and B. This cover 51 is preferably held in place by transversely ex; tending lugs at the top and bottom of rear casting B, said lugs having vertically extending grooves in them adjacent to the outer ends of tlievertical members of rear casting R, andby .a nut 52threaded on a provided a wire 54 passing through a small application of the protective device hereinbefore described to one system of electric interlocking In this system of electricin terlocking, each switch, signal or'other part controlled by the l interlocking plant, which are commonly termed functions, is controlled by a slidable bar 55, commonly termed a lever, which is provided with a suitable handle 56 for facilitating its manual operation. Only one lever 55 and its associated parts are shown in Fig. 10, and it is to be understood that in practice there are several such levers in each interlocking plant, and thateach lever and its associated parts constitutes a unit suitable for controlling one of the functions. The difierent levers 55 of the interlocking plant are interlocked by any suitable formof mechanical interlocking well known in the art, and this mechanical interlocking is actuated by each lever 55 by means ofalink 57 the upper end of which carriesa roller engaging with a cam slot 58 formedin the body of the lever 55, whereby the reciprocating movement of the lever 55causes a vertical movement of the link 57 and its connected parts. V The lever55 is supported by a suitable frame or guide 59, and on this guide is pivoted a spring pressed latch 60, said latch being arranged so that when its righthand end is raised, that end will cooperate with certainshoulders formed in the lower edge of the lever 55 so as to limit the longitudinal movement of said lever in certain of its positions. Also pivoted to the guide 59 is a dog 61 which is arranged to catch under the righthand end of the latch 60 and hold said latch in' its upper locking position; and arranged so as to swing the dog 61 under the latch 60 is a cam or tumbler 62 which is pivoted to'the guide 59 and is provided with Lip-standing'teeth adapted to be engaged by teeth along theunder edge of the lever 55, so that said cam is rocked as said lever is moved back and-forth. Below the dog 61 is arranged a pair of coils 63 constituting an indication magnet I. This indication magnet I is preferably of the type shown and described in the application of Frank T. Casper Serial Number 159,201, filed April 2, 1917. The armature 64 of the indication magnet I is connected to a rod 65'which extends upwardly into position to strike the dog 61 and trip it out of engagement with the latch 60 when said armature 64 is at tracted upwardly by coils 63. p The lever 55 is arranged to open and close certain circuits at certain positions in its movement, and for this purpose there is connected toisaid'lever a rod 66, to which are attached two metallic: contact blocks 6? and T68. insulated from eachcother. Four as the lev er is mov d normal POSltlOlfifl 7 i 2nd, an'outermost 'posltlon, which s conveniently termed the reverse position 3rd, ELPOSltlOIl' near the lnnermost or nor-.

mal' position in which the contact blocks67 and 68 are in contact with the corresponding "pairs of contact :springs70-and 72, but in I I which the link 57 has not been forced down- I wardby the cam -slot 58,to its lowermost 2 position; and.

ing pairs ofcontact'springs'69'and71, but in which'the link 57 has not been raised to 7 its uppermost'position, this position of the; V lever being conveniently termed the reverse position, this positionof the leverbeing con- .Veniently termed 4th; a position near outermost or reverse, position in which the contact blocks 67 andf68 are in contactwith the correspondindication position.

A further descriptionindetail of theconstruction of the) parts associatedwith the interlockingv lever "is not deemed necessary for a, clearunderstanding of v'theconstruction and operation of the protective device embodying this invention.

Supported-in any suitable way adjacent to the lever 55 is an indication selector comprising two. electromagnets 73 and. 74 between which a contact bar 75 of magnetic materialispivoted at one end so as to be' rocked'back and forth by theattraction of said. electromagnets The-contact bar 75;" is in contact with a strip76" at all time's; and with strips 77*and Y 78, respectively, in

' tioned patent, that during the first unlocking the two extremes of its movement] 'ing current,'-as atransformer 79 and asso-V Theparts of the electric interlocking system'shown in Fig. 10 so far described are located in a tower or cabin, -in which'is 5 also located a suitable source of alternatciated with each'unit lever is the protective-device shown in Figs. 1. to 9 inclusive and hereinbefore described. In Fig;- 10'the protective device has been illustrated diagrammatically} only the coil 6 and'the' two' contactsprings- 40 being illustrated. r

1 In Fig. 'IOythe unit lever 55 and its asso g 7 "formed by the protective device embodying ciated parts are shown as used for operating a switch, but it is to be understood that the protective device embodying this invention is applicable in thesame way to cases wherej;a signal oroother function is operated. 'Themechanism for operating the. switch is shownldiagrammatically and is 55 has four "significant -p0si- V the normal indication preferably of the". type shown. and described 7 pensating' vfield- '82. This operating motor M isof anysuitab1e type which is capable of. being operated 1 by alternating current "in onedirection or the iother upon reversal of the connections to its field or armature and which is also capable of generating dynamically a direct currentgwhen its armature rotates idly after each operation of the function...v I 1 The "supply of-current-to the motor'M is controlled by a. circuit controlling device,

commonlytermed a pole changer, which comprise's'four pairs of contact springs 8-3,

84, and 86 and movable-contact pieces 87 88 89 and 90 carried by a contact-carrying block 9-1 of insulating material. The a contact-carryingblock 91 isjoperated me f chanical ly in correspondence withthe move- 7 ments of thejswitch, in the manner shown and .describedejin detail in the above mentioned patent. This contact-carrying block '91 is also arranged to be" operated electrically by pole changer operatingcoils 92 and '93. -Also forming azpart of the pole changer is; another contactcarrying block "9.4 upon which are supported two contact 7 s I pieces 95 and 96 which'are adapted to make electric contact with pairs of contact springs 97 and 98 in different moved positions of said contact-carryingblock 94. The contactcarrying block 94 is operated mechanically in correspondence with the movement cf the operating parts ofthe switch machine.

Referring to'Fig. '11, which shows adiag'rammatic end view of this contact-carrying block 94 and its. associated contact springs, the construction of the, parts for operating this contactcarrying block is such,

as shown and described. in theabove menmovementofthe switch machine, said block 94 is .shifted from one extreme position to its intermediate position which itscontact pieces95 and 96 respectively touch the the final lockingmovement of the switch machine, ,the contact carrying block 94 is shifted mechanically to the, opposite extreme position, where its contact pieces 95 and 96 are 'iout of contact with both of contact springs 97 and 98. 1 :In order to make clear the functions perof the pairs this invention, the operation offthef system operation of the protective device under ab- 7 normal operating conditions will be pointed 115 palrs of contact springs 97 and 98. During weave out. Assuming the parts of the interlockin the .reverse indication position.

ing system to beintheir normal position as shownin Fig. 10, when the lever 55 is pulled out toward its reverse position,it may be moved without opposition to the point where springs69 and contactlblock 67, conductors 102 and 103, contactsprings 85 and contact piece 88, conductor 104 armature 80of the operating motor M, conductor 105, contact springs 86 and contact piece 90, conductors 106 and 107, operating field 810i themotor,

V conductors 108 and 109, contact finger 10 of the protective'device,'jumperllO, and

' mence the operating movement of the switch o. 7 machine. During the first part of the unconductor 111 back'to the transformer The circuit j ust traced supplies current the operating-- motor and causesit to comlocking movement of the switch machine, the contact-carrying block 94 is shifted to 1ts intermediate position, whereupon current may also flow through theopole changer op- V crating co1l93 in" a branch CIICUltWlllch may be tracedias follows: Commencing at the contact spring 85fto which the conductor 10?) 7 is connected, conductor 112, pole changer operating coil 93, conductor 113, contact springs 98 and contact piece 96, conductor 114 to" the conductor ,109 and thence back to the transformer79, along'the samej path as 'hereinbefo're traced. The, purpose of energizingthe polechanger operating coil 93 is fully set fort-11in the Patent Number 800,24;6,

hereinhefore referred to. The circuit above traced also causes current-to flow through the indication selector magnet 7 3 .whichaat-' tracts the contact bar 7 5, fro1n the position shown in Fig. 10 to itsfopposite position where it establishes electrical connection between the contact strips 76 and 77. a

After the switch machine has operated to throw the switch, during the final locking movement, the contact-carrying blocks91 and 9%, of the pole'changer are shifted me- ;chanically by the" mechanism of the switch machine from their existing positionsto the other extreme positions, opposite to that shown in FigQQlOL The movement of the contactcarrying block 94 interrupts the branch jcircuit through the pole changer operating coil 93, and the movement of the contact-carrying block:91 interrupts the circuit supplying current to; the operating motor M. The armature 8.0 of the motor M, however, continuesfto rotate due to its acquiring momentum and generates a direct cnrrent which flowsin an indication-oircuitwhich may be traced as follows Connnencingatom brush of the,,a1-1nature'8O, conductors 104 and 115, contact springs 84: and contact piece 89, conductors'116 and 107, "operating field 81, conductors 108and 109, onecontact finger 10 of theprotective device, jumper ,110,

the otherlcontact finger 10 of the protective device, conductor 117, coil 6 of the protective device, conductor 11 8, coils" 68 of the indication magnet I, conductor 119, contact strip 76, contact bar 7 5, contact strip 77,

conductor 120, contact springs 7 land contact block 68, conductors 121 andl22,contact, springs 83 and contact piece 87 1 and conductors12 3 and 105 hack to theo'ther brushjof. the armature 8O ofithe motor. This direct current, generated dynamically by'the rotation ofgthe armature of the, operating motor M, flows throughlthe coil 63 of'the indication magnet I, and being direct cur rent, is eii'ective tolift'the' armaturefie and trip the dog 61, thereby releasing the latch GO'and permitting the lever 55to heo rnoved to its full reverse position. The indication current also flows through the coil 6 of the protective device, but since tlllS'PI'OtGCtlVG T device is responsive only to'alternating current, no effect, is produced. v

It will be noted that in the operation just described, the pole changer operating coils 92 and 93 are connected throughthe pairs of contactsprings 97 and 98 and the contact piecesf95, and 9,6 to the conductor 114501011- ne ltcd to the re'tijirn conductor 109 after the first, unlocking movement of the switch machine, so that these pole changeroperatingjcoils may be used to reverse the switch in mid-stroke, if necessary, but-that these .pole changer operating coils ar'e disconnected from the conductor 11 1v during the final locking movement of the switch machine and prior to the establishing of the indication circuit. .This part. oflthe operation of the interloelrii'ig system results from changing the contact springs97 and 98, sothat they make contact with thecontact pieces and 115 96 only when the contact-carrying block 9% is in its intermediate position. Referring to Fig. .10, it can heseen that, if 7 the pole changer operating coil 92 were connected to the conductor 114: when the indication circuit hereinhefore traced "is established, the

branch circuit through this I-coil 94 would form aconducting path'in parallel withtheindication magnet I andwould deprive said indication magnet of partof the indication current. Where the switch machine is operated by direct current, the pole changer operating coils. may be madeiof high ohmic resistance so that their shuntmg effect upon the screw stops 15. The righthand or front ends of the links" 34 a1'e;held against movement by the spring32 associated with the handle H,'and,these screw stops 45are so adjusted that the point or thepivotal con 7 nection between the-pairs of links. 35and lrnowntoggle :jointQffThe leverL is held by the spring-pressed plunger 23 in =the1 pos1- tion shown in Fig. 2 where itsinclined face 3a is'below the' line connecting the pivotal jpoints of theends'ofsaid pairs of links, so that the contact'fingers iOare pressedtightly against'their cooperating contact pieces 42, in accordance with the; principle of thewell ,bears againstthe' stop pin ,22 and this stoppin 22 is preferably adjusted so that the upper end of the. lever L does not quite touch the upperjprojection15'of the vane 7 support S, forthe reason explained hereinafter. Y r

f When alternating. current flows through the coil 6, the vane let is attracted 'npwardin accordance with the principles governing the operation of the well known'vane type *relay, and after a certain amount ofidleor free movement 37' andthe clearance between the'projection due to-the width of the slot .15 of the vane support S and the'lever' L,

7 the right;

[substantially as shown in Fig. 5. 'As exthat is,un'til the'pointof contact said upward projection 15 strikes the-"lever TL and moves the uppe'rendof said lever to the right." Due to therelative proportion of the parts andv the relative positionswh'ich tinue furtherflmovement of said vane-and lever. As the vane'14 moves upward, the

lower edge of the slot; 37 therein engages the pin 36 and carries the pomt of pivotal connection between the pairs of links 35 and 34: above the line connecting the pivotal points of the ends of said links, whereupon the contact fingersL'O commence to move to continues until the contact fingers are opened and the partsassume the positions plained hereinhefoie, the opening of one of the contact fingers 40 interrupts the flow of alternating current through the coil 6, but

the parts are held in their operated po iti n I the spring 25. a H

' To restore the protective device to its normal condition,the operator presses down- -ward 'on the handle H, and the lug 30 1 of this handle engages "with the curved This movement of the parts shoulder 19 of the lever L (see Fig. 5) and causes theupper end of said lever to be -moved in a counter-clockwise direction, as

viewed in Fig. 5, against the oppositionof the spring 25, thereby permitting the vane 1a to move downward and-bring the pairs of links 34: and 35 substantially into, alinement. 1n moving the handle H downward, however, the pin 33 and the righthand ends of the pair of links 3% are moved to the right, so that, although. the pairs of links 34.- and 35' are straightened, the contact fingers 40 are still held opened; and this condition will exist so long as downward.pressure is maintained on the handleH. 'lVhen the operator releases the handle H, "the spring 3 2, aided by the-resiliency of the 0011- tact fingers 40, restores-the parts to the nor-1 mal position shown in Fig. In case the :cross, groundor the like, which previously caused the flow of alternating current through the coil 6 of the protective device, still exists, the vane 14. is immediately moved upward, and the same movement'and opera tion of the parts hereinbeforedescribed is produced to cause immediate opening of the contactfingers 10. It should be noted that the operator cannot prevent thissecond operation, because any attempt on his part to move the handle H. upward, so as to keep the contact fingers 4O closed, is ofno avail,

and any attempt on his part to prevent this operation by moving the handleH downward only 'res-ultsin the earlier opening of the contact fingers 40. The same operations will be repeated so long as the cross, ground or the like exists andso long as the-operator attempts to restore the protective device From the foregoing it can be seen that after the protective device has operated, the

circuitswhich it opens cannot again be closed until the parts of the protective device" are in such a position as to be immediately capable of reopening these circuits. Consequently, the operator of the interlocking plant cannot carelessly or maliciously restore a protective device while the cross,

ground or; the like exists, nor can he maliciously prevent the proper operation of the protective device or detract from its eihciency by manipulation or by maliciously fastening down the handle In some cases, where repairsare to. be made, or for some other reason, it may be desired to trip the protective device manually. As pointed out 'hereinbefore, the

downward movement of the handle H, when" the parts are in their normal position, causes an opening of the contact fingers 40, but in 'order to maintain these contact fingers opened it isnecessary to fasten or hold down the handle H. To avoidthis trouble and annoyance, the manually operable plunger 46 is provided. When this plunger 46 is pressed inward by the operator against the opposition of the spring 458, the being in the normal position asfishown in Fig. 4:,

the head of said Jpl'unger.engagesftherlaterally projeoting pin'18 of the'vane support S and causes" clockwise movement, as viewed j i ln-Flg; 4,;of said, vane support and the lever L, with theresult of tripping. the protective 7 device in the same wayaasif alternating currentwere to fiowthrough'the coil,6. f Afhereinbeforefdescribed. V I Yarious modlficatlons and changes may be vmade 1n the particular form of construo tion vand arrangement;of parts [of the "pro-i tective device shown and described, Without] 7; materially i changingithe functions and ad vantages of the device, and ithout depart- "ing frommy: invention. Whilefthe; prot'eci tiveidevicehas been illustrated as arranged in r so-"as'to disconneot only the 'partieular func-.

"tion. affectedeby aa crossait is obvious that V thesame scheme may be-e'xtencledto include or sections thereof; Also:the,protectivefde V vice embodying this invention ji's'fsuscept-ible of application to electrieinterlockingsys -f V '7 teens o-f'other types other than the particular V While i'Ijhave described the construction and system shown and described. '1 Consequently,

I 1 operation of one physical embodiment of my invention, I desire to "have; it understood; lthatthisl'particularembodiment selected is merely, illustrative and does not eXh aust the possible physioal; embodiments of the idea neticjdevice includinga movable member, a handle; for restorln'gfsald movable member 't0'1t S normalposltlomaffixed contaotplece r of means underlyingmy invention;

3 jVVhatl claim "asnet'vrand desireto secure byL'etters IPatentof-the Unitedstates isz" 40' I {1, A protective 'c'levlioev for {electric interlocklng 7 systems compris ng an-rl 'electromagand: a} V cooperatingtmovable contact finger,

' twolinksfhavingtheir-adjacentrends pivotallyj connected and having their opposite endsconnected to said 'contafct finger and "said handle respectively, said links being substantially in ,alinement hen contact gerisj inj its closed position,-;the restoring movement of said handle ,cau'singf bodily movementiof thelinks'to move said contact finger to its open position, and means opera said links andacting uponmovement of said 7 -*"movable member jco' its operated position to v throw thelinksout o fr-a lineme'ntand'to move 7 V .Jthecontact finger toiitsfopenl position; 55360? f" locking. systemseomprising a: ifiiied "contact piece and a cooperating movable eont'aot fintively connecting said movable 'membenand 295A protective device for electric iinter iger, an electromagnetic device including a 'movable member; pivotally connected: links operatively :goonnected to said'contactjlfinger links operatively connected to said con-tact finger and. controlling the movement thereof, resilient means tending to move said links "out 0f alinement in either direction, a fixed substantially out lofjalinement inone direcv tion, and-"means oonneoting; isaid movable member-:and Z sarddinks and adapted to cause vvhilein its operat tain said veonstituting an operative connection between 7 said movable member and said links,

ated With said movable member.

movable: contact finger, pi'votall'y connected stop forpreventing? movement or said links .and ont ollinsithei ov ne tth e e and an over-center throwing device associ- V .70 j A; protective device for, electric interlQOklllgj systems vcomprlslngfan electromag -f {:HQtlQdBVlQB nclud ng a omovable member, a

'movementfof saidlinks'out of alinement in the-other direction afvvay' from said stop. V

4;; 'protectivedevice for electric intercontroller 'uponenergization of the coil, and

manually; operable means for restoring said movable memberto its normal position, said ;;means; acting to maintain said circuit con-- n' n ep nden yfi troller in its openiposi said movable member I adapted-to hold said-movablememberin-its rouit vcontrol l'er governing the movement ofsaid circuit "con movable member for-Top erating said circuit [looking systems.- comprising a normally closed 1 i circuit controller, an electromagnetic device including an operating coil 1and a movable {member Qfor opening said circuit the Wholeiinterloeking plant or {any section 7 normal position and 'aotingaftera predeter- "mined movement thereof tomovesaidrm0v 7 Tablemember'toopen sai v andto holditjin'said-open' osition.

6. A protectivefdevice'c'forjelectric interlocking'systems;comprisinga 'cirouit controller, an electromagnetic device including an operatingcoil andga movable member-torl l 0 *tr oller, and anover center throwing device 'asso,ciatedjvvith said movable member.. v 7' 7.- A "protective device forflelectric .interlocking systems comprising ai circuit con- V *troller, l electromagnetic; {means including, a' 11.5 V

r 7 controller, resilient means controlling the movement 'ofsaid;movablemember said res 'si-lie'nt means tending to, hold said circuit controller in; its closed position. and acting after a predetermined movement, thereof, to, move said 'cireuiticontroller toitsropen posij-r tion, and:manuallvjoperable means 'for 're storing said "movablememberrto its normal posjltlon, =sa1d= manua y ope a e m an ,edpo i ion otingto mainf tion- 1 8; In an,

circuit" ontroller in its open iposirent; a function adapted to be operated by alternating current; va return connection from sald functlon to sald source; a c1rcu1t closed when said function is at rest, a circuit controller included in said return connec tion; an electromagnetic device comprising an operating coil included in said circuit and a movable member, said movable member being operated by the flow of alternating current in the operating'coil to open said circuit controller; and manually operable means for restoring said movable member to combination: a source of alternating cur-.

rentan electrically operable function ineluding amotor adapted to be operated by alternating current and to generate direct current dynamically after each operation of the function; a return connectlon from said function to said source, an 1nd1cat1on mechanism; a conducting path for current to flow from said return connection through said indlcation mechanlsm; c1rcu1t controlhng means for lnterruptmg sald return connecrtionand said conducting path; electromagnetic means for opening said circuit controlling means When alternating current flows in said conducting path; and means associated with said electromagnetic means for mechanically holding said circuit controlling means in its open position. AINSLIE T. CARTER.

Copies of 'this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). 0. 

